Adjustable axle control

ABSTRACT

An activating portion on one section of an adjustable wheel assembly triggers a proximity switch on a vehicle such as a field sprayer to provide a signal indicative of wheel tread. The signal is sent to a controller which controls wheel tread adjustment. Two or more assemblies may be adjusted simultaneously reduce adjustment time. The operator control is located in the vehicle cab for entering wheel spacings, providing an indication of the actual spacing and individual wheel position, and providing error and warning messages. An interlock system prevents axle telescoping unless certain vehicle conditions are satisfied, such as the vehicle speed being below a preselected point and vehicle being in the field mode.

FIELD OF THE INVENTION

The present invention relates generally to adjustable axles forvehicles, and, more specifically, to an adjustable axle control systemfor wheel spacing adjustments on agricultural implements such as fieldsprayers.

BACKGROUND OF THE INVENTION

Adjustable axle assemblies are commonly utilized to adjust wheel spacingin agricultural vehicles for numerous reasons including theaccommodation of a variety of row spacings and the following ofspecified wheel track patterns. Examples of such structures are shown inU.S. Pat. Nos. 6,139,045; 5,454,583; and 5,282,644. Although variousdevices for determining and setting axle position have been available,providing repeatable and reliable wheel spacing adjustments in auser-friendly manner with adequate interlocks to assure adjustments aremade only under proper operating conditions has been a continuing sourceof problems. Some systems require the operator to read indicia on oradjacent the adjustable axle and are inconvenient to use. Others requireeach axle assembly to be adjusted separately which is a time-consumingprocess on vehicles having numerous axle assemblies.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide animproved system for determining and setting axle position on a vehiclewith an adjustable axle. It is a further object to provide such a systemwhich overcomes most or all of the problems associated with previouslyavailable wheel spacing systems.

It is another object of the present invention to provide an improvedsystem for determining and setting axle position on an adjustable axlevehicle which is easy to operate and which provides reliable feedback sothe operator can readily determine axle adjustment and make changes inwheel spacing from the operator station of the vehicle. It is a furtherobject to provide such a system which facilitates adjustment of two ormore axle assemblies at one time to reduce the time necessary forcompleting the vehicle tread adjustment.

It is still another object of the present invention to provide a systemfor determining and setting axle position on an adjustable axle vehiclehaving an improved structure for indicating the amount of axletelescoping. It is a further object to provide such a system having animproved interlock system.

In the embodiment shown, a strap on the side of a telescoping axle kneeincludes spaced portions which trigger or activate a sensor or switchattached to the mainframe axle for each adjustable axle assembly on avehicle such as a field sprayer. Each spaced portion represents apreselected distance of travel allowing numerous wheel tread settingsbetween the maximum and minimum spacings. Telescoping of the assembliesis controlled by a chassis controller, and two or more assemblies may beadjusted simultaneously if desired to reduce adjustment time. Theoperator control is located in the vehicle cab for entering wheelspacings and includes a readout providing a convenient indication of theactual spacing and individual wheel position. The readout also provideserror and warning messages. An interlock system prevents axletelescoping unless certain vehicle conditions are satisfied, such asvehicle speed below a preselected point and vehicle in the field mode.Failed sensor indications or indications that the telescoping axle failsto fully extend or retract are also provided. The control includes areset feature for easily calibrating tread adjustment when the axles aretelescoped to a limit position. The operator control is easy tounderstand and operate, and the readout provides a clear indication ofthe state of all the telescoping axle assemblies. Warning and errormessages help the operator to quickly diagnose system problems.

These and other objects, features and advantages of the presentinvention will become apparent from a reading of the detaileddescription below in view of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the user input and displaydevice and controller for an adjustable axle vehicle.

FIG. 2 is a view of a portion of an adjustable axle assembly for thevehicle showing a transducer and actuator structure for providingposition signals to the controller circuit.

FIG. 3 is an enlarged perspective view of the telescoping portion of theaxle assembly of FIG. 2.

FIGS. 4A-4D is a controller flow chart for right front tread of thevehicle and for the tread in control.

FIG. 5 is a flow chart illustrating the programmed operation of the leftfront tread out adjustment.

FIG. 6 is a flow chart illustrating the programmed operation of theright rear tread out adjustment.

FIG. 7 is a flow chart illustrating the programmed operation of the leftrear tread out adjustment.

FIG. 8 is a flow chart illustrating the programmed operation of thetread adjust calibration.

FIG. 9 is a flow chart illustrating the programmed operation forproviding caution messages for tread sensor miscalibration and transportposition.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1 therein is shown a control and display system 10for a vehicle such as a field sprayer shown schematically on the displayat 12. The vehicle 12 includes a frame 14 supported for forward movementover the ground by left- and right-front (LF and RF) wheels 16, 17 andleft- and right-rear (LR and RR) wheels 18, 19. An operator cab 22 issupported on the frame 14 between the wheels 16-19.

The wheels are supported by adjustable axle members 26 (FIG. 2) formovement over a range of tread positions between narrowed transportpositions (solid lines of FIG. 1) and widely spaced positions (brokenlines of FIG. 1). As shown in FIG. 2, the member 26 includes a firsttubular member 34 extending outwardly from the frame 14, and afabricated knee joint structure 36 supporting the corresponding wheeland having an inner tubular end telescopingly received within the member34. Hydraulic cylinder or motor structure 38 extending between the frame14 and the tubular member 36 and connected to electrohydraulic valvestructure 40 is extendible and retractable to move the joint structureout and in to change the wheel tread.

The electrohydraulic valve structure 40 for each wheel is connected to asource 42 of hydraulic fluid under pressure and includes a control input44 connected to wheel control relay structure 46. The relay structure 46is connected to five low side driver outputs 48 of a main electroniccontroller 50 that power the individual relays of the structure 46. Thecontroller 50 and relay structure 46 control the valves 40 to providehydraulic tread adjust for the four wheels 16, 17, 18 and 19 in bothindependently and combined sequences described in further detail below.The controller 50 includes four sensor inputs 54 which receive signalsfrom corresponding transducers or sensors 56 located at each of theadjustable axle members 26 to determine the current position of thetread. A control input and display device 60 includes outputs 62connected to inputs of the controller 50 to provide request signals tothe controller to move the wheels 16-19 outwardly or inwardly. Thedisplay device 60 may be the commercially available John Deere GreenStarDisplay having a screen 64 with menu driven commands that allow anoperator to program information quickly. The display area allows viewingof operational data while on the go and utilizes audible tones to guideor alert users while operating the machine. The display 60 has a SETUPpage mode for tread readout and adjustment (shown) wherein informationsuch as actual front and rear tread widths can be displayed and desiredtread widths can be entered and displayed. Messages are displayed on amessage screen 64g.

The control and display device 10 includes all tread in and all treadout control switches 65 and 66 and vehicle transport range and fieldrange control indicators or switches 67 and 68. The transport rangecontrol switch 67 will be activated when high speed operation of thevehicle is selected.

An activating device 70, shown as a single laser cut metal piece havingupright raised activating portions 72 regularly spaced along thetelescoping portion of a knee assembly 74, moves with the assembly 74within an outer beam 76 of each of the adjustable axle members 26. Thesensor 56 provides signals to the controller 50 as the axle members areadjusted in or out to vary the tread. The sensor 56 may be a proximityswitch such as a hall effect transducer which senses each activatingportion 72. As the portion moves into close proximity of the sensor 56,a pulse is provided to the input of the controller 50. The activatingportions 72 represent a fixed axle travel distance, for example, oneinch, so each pulse represents a predetermined tread increment. Wheelspacing for a pair of front or rear axle members 26 therefore may bedetermined by:Tread=W_(s)+(S×N_((Left)))+(S×N_((Right)))where W_(s) is the initial minimum tread, S is the spacing between theactivating portions 72, and N_((Left)) is the number of pulses providedby the left transducer 56 and N_((Right)) is the number of pulses to theinput 54 of the controller 50 as the axle members 26 are adjustedoutwardly. For example, a field sprayer may have tread settings at 115inches for transport, and (120+(S×N_((Left)))+(S×N_((Right)))) inchesfrom 120 inches up to 160 inches total tread setting. An elongated slotat 78 provides a longer first increment (2.5 inches for the aboveexample).

The controller 50 controls the hydraulic tread adjust of the four axlemembers in both independent and combined sequences. In one arrangement,the user can adjust the tread of any of the four wheels using the SETUPpage of the display device 60. Each wheel 16-19 is movable outwardlyindependently of the other wheels, but all four wheels will moveinwardly at the same time under the operation of the controller 50 andthe valve structure 40.

Referring to FIGS. 4-9, therein are shown flow charts for the programmedoperation of the controller 50. Upon startup 200 and first power up 202the initial position settings are set to zero at 204. If astartup/reboot is determined at 206, the previous tread adjustmentsvalues are read from a non-volatile memory into the random access memoryof the controller 50 at 208.

After the initialization steps 200-208, the tread out switch 65 ischecked at 210, and if the switch 65 is active, the tread in valvecontrol is turned off at 212, and vehicle speed and the condition of thecontrol switches 67 and 68 are checked at 214 (FIG. 4C) beforeinitiating any tread out movement of the assemblies 26. If theconditions of the switches 67 and 68 indicates the vehicle is operatingin the transport mode, or if the vehicle speed is above a preselectedmaximum speed set for outward wheel adjustment (5 MPH), the device 10displays a message informing the operator that the vehicle speed must bebelow the preselected speed and the vehicle must be in the field mode at216. Control is then returned to 210 (FIG. 4A).

If the all tread out switch 65 is not active at 210, the all tread inswitch 66 is polled at 220. If both the switches 65 and 66 are inactive,the switches are continually polled (210, 220) until one of the switchesis activated. Upon activation of the all tread in switch 66, the valvescontrolling tread extension for the four assemblies 26 are immediatelyshut off at 222 and vehicle speed and vehicle mode are checked at 224.If transport mode operation or vehicle speed greater the preselectedminimum speed is determined at 224, the device 10 displays the messageinforming the operator that the vehicle speed must be below thepreselected speed and the vehicle must be in the field mode at 226 toadjust the tread, and control is again returned to 210.

Once the controller determines vehicle operating conditions aresatisfactory for initiating wheel tread in adjustments at 224, theposition of the right front wheel assembly 26 is checked at 230 todetermine if right front position is at the fully in or zero position,and, if so, the remaining wheel assemblies 26 are checked for fully inconditions at 232. If all the remaining wheel assemblies have been fullyin longer than a preselected time (0.2 seconds), the device 10 displaysan all tread in completion message at 234 and control is returned to210. If all the assemblies are not fully retracted at 232, control isagain returned to 210.

If the right front position is greater than zero at 230, the all treadin valves are activated at 238, and if the right front tread sensor 56has detected an activating portion 72 causing a low to high transitionat the controller input 54 (240), the right front position indication isdecreased. The decrease in the spacing indication will be S(=1 inch)unless the current indication less than 1.5 inches and the sensor 56 isadjacent the elongated slot 78. In that event, the decrease will be 1.5inches resulting in a right front indication of zero. The presentposition and width indications are then updated on the display device 60at 244 and 246. After the position update at 242, or if there has beenno low to high transition at the right front sensor at 240, theremaining sensors are checked in turn (250, 260, and 270) and positionsare decreased if necessary (252, 262 and 272). The display device 60 isupdated (254, 256; 264, 266; and 274, 276) in similar fashion for eachremaining wheel assembly. Thereafter control is again returned to 210.

Assuming that the operator activates the all tread out switch (210 ofFIG. 4A), the all tread in valves are shut off at 212 and vehicle speedand operation mode are checked at 214 (FIG. 4C). If speed is below thepreselected speed and if the vehicle is not in the transport mode ofoperation, the tread out control of FIGS. 4C-4D and FIGS. 5-7 isinitiated. The right front position is compared at 300 with the targetright front position entered into the device 60 (FIG. 4C). If the actualposition is less than target, the right front tread out valve isactivated at 302 and the output of the right front sensor 56 is checkedfor a low to high transition since the last check. (304 of FIG 4D). Ifsuch a transition has occurred, the right front position indication isincreased one increment (one inch unless the present position is zero orthe fully retracted position so that the initial low-high transition atthe area 78 indicates a movement of 1.5 inches). The position indicationon the display 60 is updated at 308. Control is returned to 210 afterthe update at 308 or if there has been no transition detected at 304,and the process is repeated. Once the right front position reaches orexceeds the target position for a preselected period of lime (300 and310 of FIG. 4C), the right front tread out valve is turned off at 312,and if the remaining wheel assembly positions are at or above theirtarget positions for the preselected time at 314, a tread out completionmessage is provided on the display 64g and control is returned to 210.

The left front, right rear and left rear tread out control operations ofFIGS. 5-7 are carried out simultaneously with the steps 300-316 of FIGS.4C and 4D described above. Once the predetermined vehicle conditions aredetermined at 214, the target positions are compared with actualpositions for the left front (400 of FIG. 5), the right rear (500 ofFIG. 6), and the left rear (600 of FIG. 7). The control operations ofFIGS. 5-7 are generally identical for each tread so only the left fronttread out routine will be described in detail.

If the position determined at 400 is less than the target positionindicating that the corresponding cylinder structure 38 needs to movethe left front wheel outwardly, the left front valve is turned on at 402and the controller checks for a recent sensor transition from low tohigh at 404. If there has been no transition, control is returned to 210and the process begins again. However, if there has been a low to hightransition since the last check, the left front position is incrementedby one unit (one inch unless the present position is zero or the fullyretracted position so that the initial low-high transition at the area78 indicates a movement of 1.5 inches) at 406. The left front positionis displayed at 408, the total front width is displayed at 409, andcontrol is returned to 210. The right and left rear tread out control ofFIGS. 6 and 7 include steps 500, 502, 504, 506, 508, 509, 510, 512 and600, 602, 604 606, 608, 610, 612, respectively, generally identical to400-412 described above. Once the wheel assembly positions are all at orabove their target positions for the preselected time at 314 (FIG. 4D),a tread out completion message is provided on the display 64g andcontrol is returned to 210.

When the operator is finished with a field, the all tread in switch 66is activated and, provided the proper vehicle conditions are present,the controller 50 activates the relay and valve structure to telescopethe knee joint structures 36 inwardly relative to the correspondingtubes 34 until the controller determines that the wheel tread is al thepreselected minimum value. After transport, the all tread out switch 65is activated, and the controller 50 causes the wheels to move outwardly,if the preselected vehicle conditions are met, until the desiredspacings set on the device 60 are reached.

The device 60 also includes a calibration page, and a calibrationroutine is initiated at 700 of FIG. 8 when the page is selected. Acalibrate instruction message is provided at on the display 64g (702)with selection of the calibration page. The operator returns the treadsto the minimum settings. The outermost end (78e of FIG. 3) of theactivation device 70 will be adjacent the sensor 56 when the tread isminimized, and the sensor outputs are checked al 704 to see if theoutputs are all high. If all sensor outputs are high, tread positionsare set to zero at 706 and a calibration completed message is providedon the display 64g (708). Thereafter, the calibration complete messageremains displayed until the page is changed on the display device 60 orthe key F is pressed on the device (710) to return control to 702. Ifthe key F is depressed, the calibration message at 702 is againdisplayed and the calibration routine begins again. If all sensoroutputs are not high at 704, either the tread is not at the innermostposition or a tread sensor 56 has failed and corresponding message isprovide to the operator at 712. The message remains until the key F ispressed at 714.

FIG. 9 shows a flow chart illustrating the programmed operation forproviding caution messages for tread sensor miscalibration and transportposition. The routine of FIG. 9 runs continually after startup andchecks each wheel position at 800, 802, 804 and 806. If any of the treadpositions indicate a reading less than the minimum tread, a cautionmessage is provided for the corresponding position at 810, 812, 814 or816 and a fault message indication is sent (820, 822, 824 or 826) forthat position. After all positions are checked, the selected transportspeed range is checked at 830. If the transport range switch 67 is notactive, control is returned to 800. If the transport speed range isselected, the tread positions are checked at 832. If all tread positionsare not in the narrow position, a caution message is displayed at 834and a fault message indication is provided at 836.

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

We claim:
 1. In an agricultural vehicle having a frame supported formovement over the ground by at least two wheels and an operator cab,axle structure for mounting and adjustably spacing the wheels from theframe, the axle structure comprising: at least one adjustable axlemember supported from and movable relative to the frame for adjustingthe spacing between the wheels; a sensor transducer providing a signalindicative of the movement of the adjustable axle member; and anelectronic circuit connected to the transducer and responsive to thesignal for providing a displayed readout indicating wheel spacing. 2.The axle structure set forth in claim 1 wherein the sensor transducercomprises a switch located adjacent to the adjustable axle member andswitch actuating structure movable with the adjustable axle member. 3.The axle structure set forth in claim 2 wherein the sensor transducercomprises a proximity switch, and the switch actuating structurecomprises a plurality of spaced members located on the adjustable axlemember.
 4. The axle structure of claim 2 wherein the adjustable axlemember comprises a first member telescopingly received within a secondmember, and wherein the sensor transducer is supported from the secondmember and the first member includes uniformly spaced actuatingstructure, the actuating structure cooperating with the sensortransducer to provide a pulse signal indicative of axle member movement.5. The axle structure set forth in claim 1 including motor structureconnected to the adjustable axle member and to the electronic circuit,wherein the electronic circuit comprises a controller having an inputdevice for selecting desired wheel spacing, the motor structureresponsive to the controller to automatically provide the selected wheelspacing.
 6. The axle structure set forth in claim 5 wherein thecontroller includes a vehicle condition input, and wherein thecontroller activates the motor structure to change wheel spacing onlyupon detection of the presence of a preselected vehicle operatingcondition.
 7. The axle structure set forth in claim 5 including a secondadjustable axle member supporting a third wheel and connected to themotor structure, and wherein the controller automatically andsimultaneously moves the first and second adjustable axle members toadjust the wheel spacing.
 8. In an agricultural vehicle having a framesupported for movement over the ground by at least two wheels, and anoperator cab supported by the frame, axle structure for mounting andadjustably spacing the wheels, the axle structure comprising: a firstadjustable axle member supported from and movable relative to the framefor adjusting the spacing between the wheels; a transducer responsive tothe movement of the first adjustable axle member and providing a signalindicative of the position of the first adjustable axle member; anelectronic controller responsive to the signal for providing a displayedreadout indicating wheel spacing, the controller including a controloutput; and motor structure connected to the first adjustable axlemember and to the control output of the electronic controller for movingthe first adjustable axle member relative to the frame.
 9. The axlestructure set forth in claim 8 including a display device located in thecab and connected to the controller providing an indication of thespacing of the wheels.
 10. The axle structure set forth in claim 9further wherein the controller includes a desired wheel spacing input,and the controller is responsive to the desired wheel spacing input toautomatically operate the motor structure to provide desired wheelspacing.
 11. The axle structure set forth in claim 9 wherein thecontroller includes an input for receiving a vehicle condition signal,and the controller is responsive to the vehicle condition signal toprevent operation of the motor structure under preselected vehicleoperating conditions.
 12. The axle structure set forth in claim 8further comprising second, third and fourth adjustable axle memberssupported from the frame and connected to the motor structure, each ofthe first, second, third and fourth axle members supporting a groundengaging wheel, and wherein the motor structure is responsive to theelectronic controller to simultaneously move a plurality of theadjustable axle members to adjust wheel spacing.
 13. The axle structureset forth in claim 12 wherein the electronic controller includes aninput device for selecting desired wheel spacing, and a readout devicefor providing an indication of the actual wheel spacing.
 14. The axlestructure as set forth in claim 8 wherein the first adjustable axlemember includes index structure cooperating with the transducer toprovide a signal in response to movement of the first adjustable axlemember.
 15. The axle structure set forth in claim 14 wherein thetransducer comprises a non-contact transducer, and the index structurecomprises regularly spaced transducer exciting members providing asignal to the controller as the first adjustable axle member is moved.16. The axle structure as set forth in claim 14 wherein the indexstructure provides a pulsed signal, the number of pulses provideddependent on amount of movement of the first adjustable axle member. 17.In a vehicle having a frame supported for movement over the ground by atleast two wheels, axle structure for mounting and adjustably spacing thewheels, the axle structure comprising: an adjustable axle membersupported from and movable relative to the frame for adjusting thespacing between the wheels; a transducer supported adjacent theadjustable axle member and providing a signal indicative of the movementof the adjustable axle member; an electronic controller connected to thetransducer and responsive to the signal for providing a displayedreadout indicating wheel spacing, the controller including a controloutput; and a motor member connected to the adjustable axle member andto the control output of the electronic controller for moving theadjustable axle member relative to the frame.
 18. The axle structure asset forth in claim 17 wherein the controller includes a vehiclecondition input for receiving a vehicle condition signal, and whereinthe electronic controller is responsive to the vehicle condition signalfor limiting movement of the adjustable axle member under preselectedvehicle operating conditions.
 19. The axle structure as set forth inclaim 17 wherein the controller includes means for checking wheelspacing for at least one limit position and providing an error signal ifthe checked wheel spacing is outside a range of acceptable wheelspacings for the limit position.
 20. The axle structure as set forth inclaim 17 including a plurality of simultaneously adjustable axlemembers, wherein the readout includes a desired wheel spacing input foroperator entry of wheel spacing settings and the controller isresponsive to the wheel spacing settings for moving the plurality ofadjustable axle members.